Control device and system



Nov. 9, 1948. H, A. WHEELER CONTROL DEVICE AND sYs'rEh 9 Sheets-Sheet 1 Filed June 11, 1945 3mm HamldAwheezer Nov. 9, 1948.

H. A. WHEELER CONTROL DEVICE AND SYSTEM 9 Sheets-Sheet 2 Filed June 11, 1945 w n M u m H H. A. WHEELER CONTROL DEVICE AND SYSTEM Nov. 9, 1948.

Filed June 11, 1945 v OIL PRESS.

4 k I 115 1 *1H 42". l9 7 1 I0 I I 9 Sheets-Sheet 3 Nov. 9, 1948. H., AL WHEELER CONTROL DEVICE AND SYSTEM .9 Sheets-Sheet 4 Filed June 11, 1945 Nov. 9, 1948.

H. A. WHEELER CONTROL DEVICE AND SYSTEM 9 Sheets-Sheet 5 Filed June 11, 1945 Nov. 9, 1948. H. A. WHEELER 2,453,170

CONTROL DEVICE AND SYSTEM Filed June 11, 1945 9 Sheets-Sheet 6 Wan- 162 A. Wheeler.

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Nov. 9, 1948. H. A. WHEELER CONTROL DEVICE AND SYSTEM 9 Sheets-Sheet 7 Filed June 11, 1945 I :hwem tm Harold A.W/zeele1? Nov. 9, 1948. H. A. WHEELER 2,453,170

CONTRQL DEVICE AND SYSTEM Filed June 11, 1945 9 Sheets-Sheet 8 Nov. 9, 1948. H. A. WHEELER 2,453,170

CONTROL DEVICE AND SYSTEM Filed June 11, 1945 9 Sheets-Sheet 9 I O In 3 w 4 -10 H "1 '3 3 3 m a a 9 sav- 9H m Emnss aud cnosmvw awe/WW, Q HarddANY/weler.

g M WIQg/i plLoTs CONTROL ANGLE- DEGREES Patented Hot. 9, 1948 TENT (EGNL BEVIGE AME 338m Harold Arthur Wheeler, Grand Rapids, Mich, as

signer to Bendix Aviation @orporation, Eaterhoro, N. 1., a corporation of? Delaware Application lane i1, 19%, Sefai N %,?65?

The present invention relates to improved controldevices and systems of theclass disclosed by application Serial No. 783,237, filed October 31, 1947, by Howard A. Alexanderson as a continuation of application Serial No. 508,724, filed November 2, 1943, now abandoned, and application Serial No 551,036, filed August 24, 1944, by How- 23 Claims. (CR. 223-lill) ard A. Alexanderson, and application Serial No.

581,878, filed March 9, 1945, by Howard A. Alexanderson and Harold A. Wheeler. More specifically, the present invention relates to a novel and improved control mechanism for a supercharged aircraft engine which provides means for effecting automatic control of two or more intake manifold pressure selection programs for such an engine in response to an operating condition thereof.

An object of the invention is to provide novel means responsive to the intake manifold pressure for adjusting a throttle valve so as to approximate predetermined pressure values together with a novel pair of adjustable members for selecting such pressure values and means for selectively actuating one or the other of said members into operating relation in response to an operating condition.

Another object of the invention is to provide a novel adjustment means for directly actuating an automatic carburetor throttle control in a first sense, and a second novel intake. manifold pressure responsive means for directly actuating the throttle control in an opposite sense so as to maintain a predetermined selected pressure value, which value is variable in accordance with a first selected program, and adjustable means for varying such value in accordance with a second or more selected programs.

Another object of the invention is 'to provide a novel selector linkage arrangement, whereby the datum of the boost control may be selected in accordance with two or more predetermined programs.

Another object of the invention is to provide a novel control mechanism for selecting in accordance with a first selected program the intake manifold pressure of the aircraft engine, including novel adjustable means for varying the relationship of the intake manifold pressure of .the aircraft engine in accordance with a second selected program brought into operation by a predetermined operating condition.

During the operation of so-called water" or anti-knock fluid injection systems for suppressing predetonation in internal combustion engines, an increase in the air inlet pressure of the induction system for the engine is permissible and desirable in order that greater engine power may he obtained than when such injection system is not in operation. 'fliereicre, an object of the present invention is to provide a novel regulator responsive to operation of such an injection system for efiecting a predetermined increase in the air pressure in the induction system Another object of the invention is to provide a novel regulator for effecting smooth control throughout the range of. operation of the "antiknoc fluid injection system.

Another object of the invention is to provide a novel regulator for effecting automatic control in accordance with a first predetermined program during low speed supercharger operation, and automatic control in accordance with a second predetermined program during high speed supercharger operation.

Another object of the invention is to provide a novel regulator for effecting automatic control in' accordance with a first predetermined program during operation of the supercharger at low speed; a second predetermined program during operation of the supercharger at high speed; and a third predetermined program during operation of the provide manually achustable means or automatic altitude responsive means for effecting such oper ation.

These and other objects of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpom of illustration only, and are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings:

Figure 1 is a side view showing the control mechanism;

Figure 2 is a view with the control mechanism of Figure 1 turned over and the opposite side broken away to better illustrate the operating Figure is an end view of the control mechanism;

Figure 6 is a diagrammatic view of the operating mechanism;

Figure 7 is a schematic view showing the control mechanism in operative relation with the aircraft engine controlled thereby;

' Figure 8 is a diagrammatic view of an altitude responsive device for controlling the speed of the supercharger and effecting the operation of the regulator;

Figure 9 is an enlarged perspective view illustrating the range adjustment linkage;

Figure 10 is an enlarged perspective view illustrating the cam follower linkage arrangement;

Figure 11 is an enlarged plan view of the leaf spring arrangement for the cam follower arms;

Figure 12 is a graphical illustration of the operating characteristics of a typical control mechanism embodying the present invention.

The control mechanism as shown in Figures 6 and 7 is preferably operated by a main control lever i pivotally mounted at 2 within the cabin of an aircraft. There is pivotally connected to the control lever one end of a main control rod 3.

the carburetor 21 to a suitable air supply or 441s coiled about the shaft 43 and one end 45 As shown in Figure 6, there is pivotally connected at the opposite end of the main control rod 3 at 4, an arm 5 mounted on a main control shaft 6 and positioned exteriorly of a casing I as shown in Figures 1 and 3. The casing I houses the novel control mechanism and may be conveniently mounted on a bracket 1A as shown in Figures 2 and 5.

Asshown in Figure 1, there is formed integral with the arm 5, a second arm 9 likewise mounted on the main control shaft 6 and positioned exteriorly of the casing I. Movement of the arm 3 may be limited as indicated in Figure 6 by a stop 9, which is arranged for engagement by an adiust able limiting screw 9A provided on the arm 8 and a second engaging arm l0 formed integral with the arm 8.

The main control shaft 6 extends into the casing 1 and is rotatably mounted on suitable anti-frictional roller bearings, not shown.

Positioned within the casing I and fixedly mounted at the inner end of the main control shaft 6 is a crank pin I I, as best shown in Figure 2 The crank pin I I has pivotally mounted at the free end thereof a walking beam I2. The walking beam I2 is pivotally connected at one end to a link i3 which is in turn pivotally connected at the other end to an arm l4 of a bell crank lever l5. as shown in Figure 2,. The bell crank lever I5 is mounted on a, shaft IS.

The shaft I6 is mounted on anti-frictional roller bearings, not shown. and projects through the cas ing I, as shown in Figures 5 and 6. Mounted at the outer end of the shaft I6 is an arm II having pivotally connected at the free end a throttle control rod I9 for adjustably positioning a throttle valve l9 positioned within the air intake conduit of a conventional aircraft internal combustion en ine, as indicated diagrammatically in Figure 'I.

The throttle valve I9 is arranged so as to regulate the pressure at the intake manifold 20 of the engine 2I by regulating the air inlet through conduit 22 to a supercharger 23. The supercharger 23 is driven by an aircraft engine 24 through a drive shaft 25 and change speed gear or hydraulic coupling 26. The supercharger 23 is arranged to supply air to the intake manifold 29. A carburetor 2I isprovided on conduit 22 of conventional type and a conduit 28 leads 1mm intake scoop 29.

Fivotally connected to the arm 3, previously described. is one end of a linkage rod 33. The opposite end of the rod 30 is pivotally connected to one end of a lever arm 3| mounted on a pressure selector shaft 32, as shown in Figure 6. The shaft 32 projects into the casing I and is preferably mounted therein on bearings 32A and 323.

The shaft 32 has fixedly mounted thereon, cams 33, 34, and 35 which may be adjustably positioned by the adjustment of the shaft 32. The earns 33, 34, and 35, have provided variable cam surfaces 36, 3I, and 38, respectively, which are arranged to bear upon cam follower members 39, 49, and

4| as will be explained hereinafter. so as to operably connect the shaft 32 to an adjustable frame or lever member 42. As shown in Figure 8, the lever 42 is pivotally mounted within the casing I on a shaft 43.

There is connected to the lever 42 at the lower end, as viewed in Figure 8, a spring 44. The spring bears upon a fixed member 46, while the opposite end 41 biases the lever 42 in a counter-clockwise direction about the shaft 43. Projecting from the lever 42 at a point intermediate the opposite ends thereof is a pin 43 to which there is pivotally connected an end 49 of a novel range adjustment floating lever 59.

The floating lever 53 is pivotally connected at a point 5|, intermediate its opposite ends to one end of a linkage arm 52. The linkage arm 52 is operatively connected at the opposite end to a pressure responsive mechanism indicated generally by the numeral 53 which will be described hereinafter.

Servo-motor mechanism A third link 54 is pivotally connected at one end to the floating lever 59 at an end55 opposite from the end 49. The opposite end of the link 54 is affixed to a slidably adjustable member 56 for controlling a servo-valve of conventional type. As shown in Figure 2, the member 56 is slidably mounted within a valve sleeve 51, positioned within the wall of the casing I. Carried by the servovalve control 56 is a tension spring 58 which exerts a force biasing the link 54 toward the floating lever 50. The valve sleeve 51 has provided ports 58, 59, 60, BI and 62, as shown in Figures 2 and 6. The ports 59 and 6| are connectedby suitable conduits 63 and 64, respectively, to a servo-motor indicated generally by the numeral 65, while aconduit 66 is connected to the port 60 and serves as an inlet to the servo-valve of a suitable fluid medium under pressure such as oil under engine pressure for operation of the servo-motor 65. A drain conduit 61 is further connected to the ports 59 and 62 and serves as an outlet forthe fluid pressure medium supplied to theservo-valve in the conventional manner.

As shown in Figures 2 and 6, a servo-piston 63 is slidably mounted within a cylinder wall 69 of the servo-motor 65. The piston 68 is connected to a piston rod I0 in any conventional manner. A tension spring II biases the piston 63 in a direction tending to slide the rod I0 outwardly from the cylinder 69 for a purpose which will be explained hereinafter. Movement of the piston 69 in response to the biasing force of the spring II is limited by a collar I2 against which the piston 68 abuts in the extreme biased position.

As shown in Figure 2, suitable telescoping tubu lar members 13 and I4 are provided for protecting the spring II and limiting the extent of movement of the piston 66 in the opposite direction.

The conduits 63 and 64, previously described, lead to opposite sides of the piston 66 so that adjustment of the servo-valve control 56 to the left of the neutral position shown in Figure 6, will cause the conduit 23 to serve as an inlet of pressure to the servo-motor 65 and thereby exert a biasing force upon the piston 66 to the right. Likewise. adjustment of the servo-valve control 33 to the right of the neutral position shown in Figure 6, will cause the conduit 66 to serve as an inlet of pressure to the servo-motor t8 and exert biasing force upon the piston 68 to the left. Thus it will be seen that in the conventional manner the direction of movement of the piston rod 66 may be controlled by the adjustment of the servo control valve 56.

While therehas been shown in the present embodiment of the invention a hydraulic control and power means, it will be readily seen that other forms of controls and power means such as well known, mechanical and electronic controls and power means, may be readily substituted therefor.

It will be further noted that the outer end of the piston rod 16 under control of the power means aforesaid, is pivotally connected by a link to the opposite end of the walking beam I! from that at which the link I3 is connected, as previously described. It will thus be seen that the adjustment of the walking beam l2. and accordingly the throttle control shaft I6 is de pendent upon the effect thereon of the adjustment of the main control shaft 6 and the servomotor 65. a

The adjustment of the servo-motor 65 is dependent upon the adjustment of the pressure- Pressure responsive mechanism The pressure responsive mechanism 53, previously noted. comprises preferably a pair of bellows I6 and I1 mounted within the casing I, as best shown in Figure 3. The bellows I1 is preferably partially evacuated and balanced by a coil spring 18 mounted within the bellows 11 so as to act against the biasing force of the bellows 16. A wall I9 formed within the casing I has mounted thereon the bellows 16 which is connected through a passage 66 passing through the wall 19, and a conduit 6| connecting the passage 80 to the intake manifold 26 of the internal combustion aircraft engine 24, as shown in Figures 6 and '7, in such a manner that the biasing force of the bellows I6 will vary in response to the intake manifold pressure. A plate 82 is mounted between the bellows I6 and I1 and is movable upon variance in the pressure exerted within the bellows 16, as is well known in the art. The plate 82 has provided a projecting arm 63 to which there is pivotally connected an end of the linkage arm 52 previously described. The opposite end of the bellows I1 is mounted on a plate 84 secured in the side wall of the casing 1 as shown in Figure 2.

From the foregoing it will be seen that the adjustment of the servo-valve control 56 will be dependent upon the intake manifold pressure act- 6 ing upon the pressure responsive mechanism 63 and the corresponding adjustment thereof in relation to the adjustment of the operating cams II, 34. or 35. It should be pointed out here that the tension exerted by the spring M and acting upon the arm 42, has a considerably greater biasing force upon the servo control valve member 66 than the force exerted thereon by the relatively light tension spring 68 mounted on the member 66.

Thus it will be seen that in normal operation a decrease in the intake manifold pressure due to a rise in altitude for example, decrease in atmospheric pressure or other cause, would aflect the bellows l6 and ill? so as to cause the relative contraction of the bellows i6 and the relative expension of the bellows 31. Such action would cause the movement of the plate 92 and the lon itudinal movement of the linkage arm 62 toward the left, as viewed in Figures 2 and 6.

Since, as previously explained, the spring 46 exerts a greater biasing force than the spring 58, it will be readily seen that such longitudinal movement of the arm 52 would cause the floating lever 56 to pivot in a counter-lockwise direction on its pivotal connection to the arm 42 resulting in a corresponding longitudinal movement of the link 54 and servo control valve member 56 to the left.

Thus with the control valve member 56 first in the neutral position, such adjustment of the servo control valve member 56 would cause the opening of the port 56 to the inlet of the pressure medium provided through the port 66 resulting in the shifting of the piston 66 to the right as viewed in Figures 2 and 6 and the mechanical adjustment of the throttle l6 to a relative increased open position through the action of the piston rod 16 on the link 15, walking beam l2, link II, bell crank lever l5, throttle control shaft l6, arm l1, and rod l6, and thereby increasing the pressure exerted at the intake manifold 26. 1

Conversely, an increase in the intake manifold pressure would cause the relative expansion of the bellows 16 and contraction of the bellows 11, resulting in. the longitudinal movement of the linkage arms 52 to the right.

Obviously, since the movement of the lever arm or frame 42 would be prevented by the spring I, the latter adjustment of the linkage arm 52 would cause the clockwise movement of the floating lever 56 about its pivotal connection 46 to the arm 42, causing a corresponding longitudinal movement of the servo-control valve member 66 to the right. Thus with the control valve member first in the neutral position, such adjustment of the servo-control valve member 56 would cause the opening of the port 6! to theinlet of the pressure medium provided through the port 66 causing a shifting of the piston 66 and the mechanical adjustment of the throttle I! to a relative decreased open position and thereb decreasing pressure exerted at the intake manifold 26.

Thus is will be seen that there is provided automatic means'for compensating for either an increase or decrease in the pressure at the intake manifold 20, so that a predetermined standard pressure condition may be approximated. Obviously, upon standard pressure conditions being approximated, the pressure responsive mechanism 53 will cause the adjustment of the servo-control valve member 56 to a neutral position.

It will be further seen that there has been provided adjustment means whereby the value of the predetermined standard pressure condition may be varied. Thus upon movement of the concounter-clockwise direction, a clockwise movement of the main control shaft 8 will result, causing a corresponding clockwise movement of'the walking beam I2 aboutits pivotal connection to the link 18 and causing in. turn the clockwise movement of the throttle control shaft I8 so as to move the throttle I8 to a relative open position.

Furthermore, it will be seen that such adjust- I ment of the control arm I will cause also the clockwise movement of the arm 8 and a corresponding clockwise rotation of the cams 88, 34,

- and 85, as viewed in Figure 6, for changing the datum or setting of the pressure responsive mechanism 53.

Pressure selection mechanism The cams 33, 84 and 35 are operably connected to the adjustable frame or lever 42 through the cam follower members 88, 48 and H which project respectively from arm members 85, 88 and 81, shown in Figures 3, 6 and 10. The arm members 85, 88 and 81 are freely mounted respectively in spaced relation on the shaft 43. The frame or lever member 42 includes, as best shown in Figure 10, arm portions 88 and 88 provided at opposite .ends of the shaft 43, and having the upper and lower ends thereof connected respectively by plates 88 and 8|. 1

The upper ends of the arm members 85, 88 and 81 have end portions 82, 83 and 84 projecting 8 the lowest cam rise, while the lowest pressure setting results at the highest cam rise.

laterally therefrom and arranged to contact the' 7 ends of adjustable screws 85, 88 and 81 which project through the top plate 88. The cam follower arms 85, 88 and 81 are spring loaded in a clockwise direction under the biasing force of spring fingers 88, 88 and I80, respectively. The spring fingers 88, 88 and I88, as shown in Figures 3, 10 and 11, project from a spring plate I8I fastened at opposite ends by bracket arms I02 and I83 which project from a bracket plate I84, as shown in Figure 4. The plate I04 is secured to the inner surface of the casing 1, by bolts I85 and I88, and dowel pins I81 and I88. There also projects from the plate I84 the fixed arm members 48 and 46A in which is screw threadedly engaged the opposite ends of the shaft 43, as best shown in Figure 3.

, As thus shown, the' spring fingers 88, 88 and I88 tend to bias the cam follower members 85, 88

and 81 in a clockwise direction into contacting relation with the adjustable screws 85, 88 and It will be readily seen from Figure 6 that as the control lever I is adjusted in acounter-clockwise direction the shaft 32 is adjusted in acounter-ciockwise direction and thereby decreasing the cam rise of the respective cams 88, 84, and 88. The cam surfaces 88,. 81 and 88 are arranged so as to provide a diflerent cam rise program so as to effect a different program of pressure settings from the other cams, when brought into operating relation with the lever 42 through the cam follower arms 85, 88 and 81.

There is further provided novel means for selectively placing one or the other of the cams in an operating relation. The cam surface 88 of the cam 85is arranged so as to provide the lowest cam rise or highest pressure setting program of the three cams, while the'cam surface 38 of the cam 38 is arranged to provide the second highest pressure setting program or a pressure setting program higher than that set by the cam surface 81 of the cam 84.

As shown in Figures 6 and 10, the cam follower arm member 81 has a raised portion I 88 arranged so as to be operably engaged by one end of a piston rod H8. The piston rod 1 I8 is connected at the opposite end to a cup shaped piston III slidably mounted in a piston chamber I I2 formed in the end wall of the casing 1.

A fluid pressure inlet passage H8 is formed in the end wall of the casing 1 and opens at one end into the piston chamber II2, while the opposite end of the passage H8 is controlled by a valve mechanism indicated generally by the numeral II4 so as to open and close the passage H3 to a suitable fluid medium under pressure such as oil under engine pressure and entering through a second passage 8 formed in the casis drained from the casing I through suitable 81, respectively, projecting from the plate 88 of the frame or lever 42. The lever 42 is biased by the spring 44 in an opposite counter-clockwise direction, as viewed in Figure 18, but the force exerted by any one of the spring fingers 88, 88 and I88 through the cam follower arms 85, 88 and 81 exceeds the force exerted by the spring 44 on the plate 88 so that the frame 42 is biased in a clockwise direction under force of the same against the force exerted by spring 44.

It will be noted moreover, that the movement of the cam follower arms 85, 88 and 81 are limited by thecams 38, 34 and 85 which contact respectively the cam follower members 38, 48 and 4I so that the counter-biasing force exerted through any one cam follower arm and the position of the lever member 42 is dependent upon the cam surface controlling the controlling cam follower arm.

It will be noted, moreover, that as the lever member 42 moves in a clockwise direction, the pressure setting of the bellows 58 is increased. Thus the highest pressure setting is obtained at passages not shown. I

. Thus upon the valvel I4 being opened the fluid medium or oil under pressure passes through the passage II5, valve II4, passage H3 and into the piston chamber I I2 biasing the piston I I I towards the left as viewed in Figure 6. The latter action of the piston II I forces the free end of piston rod II 8 into contact with the raised portion I88 of the cam follower arm member forcing the arm 81 and cam follower member 4I out of contacting relation with the cam surface 38 of the cam 35 and in a counter-clockwise direction. During the latter action, as the biasing-force exerted by the spring finger I88 on the lever 42 is removed. the frame or lever member 42 is biased under force of the spring 44 in a counter-clockwise direction following the movement of arm 81. when a point is reached where the end of the screw contacts the projection 82 of the cam follower arm 85 such movement of lever 42 stops. Further movement of the frame or lever 42 is then prevented by the force exerted by the spring flnger 88. which biases the cam follower arm 88 in a clockwise direction. The position of the cam follower arm 85 is determined by the cam surface 36 of the cam 83, which contacts the cam follower member 88 projecting from the arm 85.

38 of cam 35. The passage II8, however, is sufllciently restricted as not to effect the position of the piston III upon the valve II4 being opened and the pressure medium or oil being exerted upon the piston III through the passage II3.

In the latter case upon the cam follower arm 81 being adjusted to an inoperative position, the cam follower arm 85 is placed in operative relation to the lever 42 as previously explained. The cam follower arm 85 has a raised portion II8 arranged so as to be operably engaged by one end of a piston rod I20. The piston rod I is connected at the opposite end to a cup shaped piston I2I slidably mounted in a piston chamber I22 formed in the end wall of the casing I.

There is formed in the casing 1 a passage I23 opening into the chamber I22 for conducting a fluid medium under pressure such as oil under engine pressure into the piston chamber I23. The latter pressure medium is conducted to the passage I23 through a suitable conduit I24, as, shown in Figure '1, having a slide valve I25 for controlling the application-of pressure through said conduit 24 from a main pressure line I28 as will be explained.

Upon the valve I25 opening the conduit I24 to the pressure line I25, the fluid medium entering the piston chamber I22 through passage I23 will his the piston I2I towards the left as viewed in Figures 2 and 6 causing the free end of the piston rod I2lto contact theraised portion II8 of the cam follower arm 85 forcing the arm 85 and cam follower member 33 out of contacting relation with the cam surface 35 of the cam 33 and in a counter-clockwise direction. During the latter action, as the biasing force exerted by the spring flnger 88 on the lever 42 is moved, the frame or lever member 42 is biased under force of the spring 44 in a counter-clockwise direction following the movement of cam follower arm 85. When a point is reached where the end of the screw 85 contacts the projection 83 of the cam follower arm 85 smh movement of lever 42 stops. Further movement of the frame or lever 42 is then prevented by the force exerted by the spring finger 85, which blases the cam follower arm 88 in a clockwise direction. The position of the cam follower arm 88 is determined by the cam surface 31 of the cam 34 which contacts the cam follower member 40 projecting from the arm 85.

The cup shaped piston I2I has a restricted passage I21 formed in the bottom thereof for draining the fluid medium from the piston I2l into the interior of the casing 1, where the same is drained from the casing 1 through suitable passages not shown. The passage I21, is however sufllciently restricted as not to effect the position of the piston I2I upon the valve I25 opening the conduit I24 to the pressure medium.

The piston I2I, thus under force 'of the fluid pressure, biases the arm 85 to an inoperative position relative to the frame 42. However, upon the valve I25 closing the conduit I24 to the pressure medium in the line I25, the spring finger 88 bellows 53.

I20 to a return position, the fluid medium within piston I2I being forced out through the restricted passage I21 under the-biasing force of spring 88 and the cam follower arm being biased to a position at which the cam follower member 33 once again contacts the cam surface 38 of cam 33.

Upon both the cam follower arms 85 and 81 being placed in an inoperative relation to the lever 42, the cam follower arm 85 is placed in operative relation to the lever 42 and the cam surface 31 of cam 34 controls through cam follower member 40 the pressure setting of the Moreover in the event the operating pressure medium is relieved from both pistons I I I and I2 I,

then since cam surface 38 of the cam 35 has thelowest cam rise, the cam follower arm 31 will control over arms 85 and 85 which are controlled by the cams 33 and 34.

As shown in Figures 2, 3 and 6, there is further provided an adjustable pin I28 screw threadedly engaged in the wall of the casing 1 and having a cleft head portion I28 providing convenientmeans for adjustment. The pin I 28 projects into the interior of the casing 1 and is arranged to contact at the inner end the arm 85 and thereby limit the extent of movement of the arm 85 in a pressure increasing direction.

A second adjustaible pin I30 having a cleft head portion I3Iv is also screw threadedly engaged in the casing I and projects into the interior of the casing 1. The-pin I30 is arranged to contact at its inner end the arm 88 so as to thereby limit the extent of movement of the arm 85 in a pressure increasingdirection. The adjustable pins I28 and I30 thus provide convenient means for limiting the maximum pressure setting afforded by the arms 85 and 85, respectively. A cover .cap I32 screw threadedly engaged in the casing 1 protects the adjustable pins I28 and I30 from accidental adjustment.

Water injection system As best shown schematically in Figure 'I, there is connected to the carburetor 21a conduit I33 leading from a suitable murce of fluid fuel for the aircraft engine. There is also provided a conduit I34 for injecting the fuel into the induction system through a nozzle I35. There is further provided a conduit I35 for injecting into the induction system through nozzle I35 a supplemental or so-called anti-knock fluid medium such as water, water-alcohol or other suitable fluid well known in the art for suppressing predetonation of the engine 24.

The conduit I36 is connected to a suitable metering device shown in dotted outline and indicated generally by the numeral I31. The latter metering device may be of a suitable type well known in the art for determining the rate of flow of the supplemental" fluid, and, since the herein invention resides in the regulator means rather than in the metering device, the same has been shown diagrammatically by the outline indicated by numeral I31.

A conduit I38 leads to the metering device I31 from a suitable source of supplemental fluid indicated by numeral I39. In the conduit I38,

there is provided a pump indicated by numeral I40 driven by a suitable power means not shown. The pump I40 supplies the fluid medium under pressure to the metering device I31. A valve MI is provided in the conduit I38 between the pump and metering device I31 for "01? and on" con- The control valve I may be of any suitable type,

but is shown herein as of an electromagnet con-,

trolled type having an electrical control circuit I42 and switch I which is preferably mounted within the aircraft cabin for convenient operation by the pilot. Thus the supplemental fluid injection system may be placed in operation by the pilot closing the switch Ill so as to ei'fectthe opening of the valve III. Conversely. the valve Ill may be closed by opening the switch I. A by-pass conduit I and relief valve Iii is provided for recirculating the fluid medium from the pump outlet to the pump inlet at such times as the valve III is closed and the injection system is not in operation.

A conduit I" is connected to the conduit Ill between the valve Ill and the metering device Ill. The conduit I leads to the control 'valve Control mechanism responsive to operation of water Infection system The control valve Ill includes, as shown in Figures 3 and 6, a plug I41 screw threadedly engaged in the casing I and projecting into the passage Iii. The plug I" has formed therein a passage I extending vertically therein and opening at the opposite ends of the plug I".

The plug I41 has laterai'ports Ill formed therein and leading from the passage II! into the vertical passage I48. A stem III- is slidably mounted in the passage Ill and-has a stem valve III at the lower end arranged upon the extreme inward adjustment of the stem III to close the lower end of the passage III to the passage of fluid medium from passage III top s se I". I

The upper end of the stem III has afllxed thereto ahead member I32. A spring I58 has one end bearing upon the plug I" while the opposite end bears upon the head member I82 biasing the stem III in an upward direction as viewed in Figure 3. The head member III and spring I52 are positioned in a chamber Ill formed in the casing I. Across the chamber I54 extends a diaphragm Iil' clamped at the outer edge between the casing I and a cap member I58 fastened to the casing 'l by bolts I51. The cap member I" has formed therein a recess III and opening into the recess III is the conduit I.

The diaphragm has a button I59 which bears upon the head member I52 of the stem Hill. A suitable oriflce or passage I" as shown in Figure 6, opens the chamber I to atmospheric pres sure or other suitable reference pressure. Thus upon operation of the water injection system there is effected an increase in the water pressure exerted in the chamber Ill. The diaphragm under "such increased pressure actuates the stem I so as to cause the valve stem I5I lower member 4| and lever 21 will control the pressure setting of the bellows ll during opera- Control mechanism responsive to-operating As shown in Figure vI, there leads from the pressure conduit I24 which controls the operation of piston I2I, a second conduit Ill. The conduit Ill opens into a piston chamber IiI of a'servo-motor I02. Slidably mounted in the pis ton chamber III-is a piston"! 'havinga spring I biasing the same in one direction, while the fluid medium entering throughthe conduit It.

When the valve I2! is shifted to the left as viewed in Figure I, a fluid pressure medium such as oil under engine pressure may be applied through the conduit III to the lower side of the piston I, whereupon the fluid medium at the upper side will exhaust through conduit Ill and outlet conduit I.

The latter action causes the piston I" to adjust the arm I" in a clockwise'direction to the position shown, at which position the supercharger 22 may be driven by shaft 2| through to close the lower open end of the passage I, Y

the variable speed coupling 20 at a relatively low speed ratio.

In the latter case, it willbe seen that the con:- duits I24 and I" are closed to the fluid pressure medium in-the conduit I20 and the cam 22 will control through cam follower member 2! and arm I the pressure setting of the bellows ll during the low speed operation of the supercharger 23.

Now upon the pilot shifting the valve I2! t9 the right as viewed in Figure I, the fluid pressure medium supplied through conduit I2I'will be apf plied through conduit I so as to shift the piston I" downward and moving the arm III in a counter-clockwise direction.

The fluid medium at the lower side of the piston III will exhaust through conduit I" and outlet conduit Itl. The latter adjustment of the arm Ill will cause the variable speed coupling 28 to be shifted so that the supercharger may be driven by shaft 25 through the variable speed coupling 28 at a relatively high speed ratio.

Moreover, the fluid pressure medium when applied through conduit IOI will also cause a fluid pressure to be applied through conduit I24 and passage I22 forcing the piston I2I in a direction for actuating the cam follower arm 25 out of operative relation with the cam- 32.

Thus with the water injection system, not in operation, and the supercharger 23 being driven at a high speed ratio, the cam 34 will control through arm 88 the pressure setting of the be]- lows 53.

The supercharger 23 is normally brought into high blower operation at relatively high altitudes, while low blower operation is effected at relatively low altitudes. It is desirable'under such conditions to provide a relatively lower pressure setting at high altitudes, while a higher pressure setting is desirable at relatively low altitudes. Through the novel cam selection means provided herein, a higher pressure setting program is provided during low blower operation than durin high blower operation.

In Figure 8, there is shown novel means for effecting such operation automatically. In the latter arrangement, there is provided a casing "I open through a conduit I12 to atmospheric pressure. Mounted within the casing "I is a bellows I13 of conventional type and operably connected so as to position the control valve I25. Thus at low altitudes the bellows I13 tends to collapse, moving the valve I25 so as to open conduit I65 to the fluid pressure medium in passage I26. This action causes the servo-motor I82 to adjust the variable speed coupling 26 so as to effect low speed operation of the supercharger 23. However, at a predetermined low atmospheric pressure'or high altitude the bellows I13 expands sufllciently to adjust valve I25 so as to Open conduit I60 to the pressure medium in conduit I26 and close conduit I65 to such fluid pressure.

Upon the latter operation the variable speed coupling is adjusted by the servo-motor I62 so as to effect high speed operation of the supercharger 23. In the latter event there will be applied a fluid pressure medium through conduit I24 to shift the low blower cam follower arm 85 out of operation, and the cam follower arm 86 into an operative relation with lever 42 during hi h blower operation.

Look out limiting means There is further provided means to lock out the automatic means, whereby upon adjustment of the main control lever I to a predetermined minimum standard pressure selecting position, the opening of the throttle I9 may be affected only by the manual adjustment of the control lever I without regard to the pressure existing at the intake manifold or the condition of the pressure responsive mechanism. This is specifically accomplished by providing an adjustable abutment rod I14 best shown in Figure 2 and explained in detail in the copending application of Howard 'A. Alexanderson Serial No. 508,724, filed November 2, 1943. The abutment rod I14 is screw threadedly engaged in the wall 19 and projects through the wall 19 into the bellows 16. A suitable cleft I15 is provided in the abutment rod I14 and is positioned ex-teriorly of the bellows 16 so that the abutment rod I14 may be conveniently adjusted longitudinally for calibration purposes. The abutment rod I14 is arranged so as to engage the plate 82 upon the pressure in the intake manifold decreasing to a predetermined low value equal to the critical standard value at which the automatic control for opening the throttle is to be discontinued and manual control alone remains.

A second abutment rod I16 is also mounted within the bellows 11 as shown in Figure 2, for the purpose of limiting the excessive expansion of bellows 16 and contraction of bellows 11 which might otherwise cause mechanical damage thereto.

There is further provided a third safety means for preventing the automatic opening of the throttle I9 past a predetermined maximum critical point, and the said safety means so arranged that such opening of the throttle past such point, may only be accomplished under the positive manual control of the lever I,

This function is specifically accomplished by providing the bell crank lever I4, previously described, with a knocker arm I11 arranged for actuating the arm I18. The arm I18, as shown in Figures 2 and 6, is pivotally mounted at one end on an eccentric pin I19 carried by an adjustment screw I80. The adjustment screw I is screw threadedly engaged in the wall of the casing 1. The position of the arm I18 in relation to the knocker arm I11 may be conveniently adjusted for calibration purposes by means of the screw I80 which extends through the wall of the casing 1 to the exterior, as shown and described in detail in the copending application of Howard A. Alerganderson, Serial No. 508,724, filed November 2, 1 43.

Carried by the arm I18 is a pin I8, on which is mounted a roller I82 arranged for engagement by the knocker arm I 11, as shown in Figure 2. There further projects from the arm I18, 9, member I83 which is arranged to engage a valve actuating stop pin I84 slidably mounted within a sleeve member. The stop pin I84 projects through the sleeve into the valve sleeve 51 where it is adapted to engage in its inward position, the free end of the servo control valve rod 56. The pin I84 is normally biased/by a spring I85 into a disengaging relation from the rod 56. In the latter position the pin I84 under the biasing force of the spring I85 actuates the arm I18 in a counter-clockwise direction against a stop pin I86 mounted in the wall 1. Upon the throttle I8 being opened to a predetermined point the bell crank lever I5 will be positioned so as to cause the knocker arm I11 to engage the roller I82 mounted on the arm I18. Continued clockwise adjustment of the bell crank lever I5 will cause arm I18 to actuate the pin I84 inward so as to prevent control valve rod 56 from being adjusted through the lever 50 to a position to the left of the neutral position. In the latter locked position a decrease in pressure at the intake manifold 20 would cause merely a contraction of the bellows 16 and the actuation of the lever 50 so as to cause the movement of the lever 42 in a counterclockwise direction against the biasing force of the spring fingers 98, 99 or I08. Further clockwise movement of the bell crank lever I5 will cause the pin I84 to actuate valve rod 56 to the right of the neutral position and the piston 68 to the extreme left hand position shown, whereupon further opening of the throttle valve I9 may be directly effected by manual operation of lever I.

Initial pressure setting and range adjustment There is further provided novel range adjustment means in the form of the lever 50 which includes as shown in Figure 9, side plates I81 and I88 fastened together by members I89 and I90 at ears 59 and 55, respectively.

Positioned between the plates I81 and I88 is a central block member I9I having a slot I92 formed at the upper end and a slot I93 formed at the lower end. A member I94 is slidably mounted in the slot I92 and the same is fastened at opposite ends to the plates I81 and I88. A similar member I95 is slidably mounted in the slot I93 and fastened at opposite ends to the plates I81 and I88.

A spring I98 is positioned between the member I95 and the block [9| and biases the block I! in an upward direction as viewed in Figure 9.

An adjustable screw I91 having a cleft end portion I98 extends atan angle through the block I9I and an end I99 is arranged so as to contact the inclined surface of a plate 288 which projects from the plate I81 and is bent at an angle thereto.

A third ear,5I projects from the block I9I Kid is adjustably positioned in relation to the cars 49 and 55 by varying the adjusted position of the screw I98. Thus with the screw I91 at an extreme inward position the ear 5I will be adjusted downward toward the ear 49, since the screw I91 under the biasing force of the spring I93. will engage-the plate 288 at a lower position than with the screw I91 adjusted more outwardly.

Through adjustment of the screw I91, the position of the ear 5| in relation to the ears 49 and 55 may be varied so as to adjust the pressure adjusting range of the bellows 53, since the position of the servo valve 56 relative to the bellows 53 and the extent of movement imparted to the servo valve for increment of movement of the bellows 53 is directly effected.

The pressure setting of one cam in relation to the others may be further conveniently adjusted by varying the relative position of the screws 95, 98 and 91 which determines the position of lever 42 relative to the cam follower arms 85, 88 and 81. The adjustable screws 95, 98 and 91, moreover, provide convenient means for making the initial adjustment for the low blower, high blower and water injection pressure programs respectively.

Casing structure As shown in Figure 2, the casing 1 includes the three sections B, C and D.

The B section houses the pressure responsive bellows mechanism 53, the servo valve 58 an the servo-motor 85.

The C section houses the throttle control linkage and is fastened to the B section at one end thereof by bolts I. A suitable sealing gasket 282 is positioned between the section B and C.

The D section houses the pressure setting mechanism and is fastened at the other end of the section B by bolts 203. A suitable sealing gasket 284 is positioned between the sections B and D.

'A removable end plate 205 carrying the adjustable pins I28 and I38 is fastened to the section, D by bolts 208. A sealing gasket 281 is positioned between the plate 285 and section D.

There is thus provided convenient means for eifecting the assemblage in a unitary device of the control mechanism herein described.

Operation The present invention provides novel means for control of various operating characteristics of aircraft engines and provides means specifically for controllin automatically two or more manifold pressure selection programs.

While the present embodiment of the invention is shown as applied to a single stage supercharger with a variable speed drive it will be readily apparent that the same may be also apstage or a variable speed drive; (3) an auxiliary stage turbo-driven supercharger or; (4) the invention may be applied as means for controlling automatically two or more selection programs.

As shown in Figure 6, the cam shaft 32 operated from the main control lever I may control any number of cams desirable-for the various engine functions or manifold pressure programs. In the present embodiment of the invention, three such cams 33, 34, and 35 are shown. Each cam operates individual cam followers, indicated herein by the numerals 85, 88 and 81 which are spring loaded to the cams by separate finger springs, 98, 99 and I08, respectively. A pressure adjusting lever 42 is biased under tension of a spring 44 into contacting relation with whichever of said cam followers is positioned so as to select the highest pressure setting.

The high blower cam follower 86 remains in contacting relation with its cam 34 during all operating programs. The low blower cam follower 85 and the water injection system cam follower 81 has hydraulic pistons I 2| and III, respectively, for releasing it from selecting or contacting its respective cam profiles.

In high blower operation, the low blower and water injection system cam followers 85 and 81 are released from contacting their cams 33 and 35 by operation of the pistons I2I and III, and the high blower cam follower 86 is positioned by cam 34 so as to control the pressure adjusting lever 42.

During low blower operation, the low blower release piston l2| automatically allows follower 85 to contact the cam 33 and to control the position of the pressure adjusting lever 42. The low blower cam 33 thus controls through cam follower 85 and lever 42 the pressure setting throughout its range of operation. While the high blower cam follower 88 is in contacting relation with cam 34, the cam selecting the highest pressure setting controls the position of the lever followers, the follower 81 under control of cam 35 calls for a higher setting than the others and .therefore dominates the control of the pressure adjusting lever 42.

The low blower release piston MI is operated by oil pressure to the oil pressure to the piston when the supercharger is operated at high blower. In low blower operation a control valve I25 is so arranged as to place the piston I2I uq der oil drain pressure so as to release the follower 85. The

control valve I25 may be manually controlled as in Figure 7 or may be controlled by an atmospheric pressure or altitude responsive device as in Figure 8.

The piston III is operated by oil pressure applied to the piston III so as to maintain the follower 81 in an inoperative relation when the water injection pressure is off as during non-operation of the water injection system. This is accomplished by a diaphragm controlled valve I I4. One side of the diaphgragm I55 is subjected to water pressure, the other side to atmospheric pressure or other suitable reference pressure. Upon the water injection system being placed in operation, the

17 increased water pressure causes the valve III to be closed so that the oil pressure is released from the piston I I I permitting the follower 81 to returnto operating relation with cam 35.

However, upon the operation of the water injection system being discontinued the water pressure applied to the diaphragm I55 is released and the valve H4 is opened so that oil pressure may once again be applied to the piston III so as to place the follower 81 out of operating relation.

While hydraulic means has been shown for effecting the foregoing operation, it will be readily seen that the same may be also eilected through electrically operated solenoids, air pressure or manual linkage and may be applied in selecting for electric, electronic or hydraulic control systerns.

Graphical illustration of operation In Figure 12, there is illustrated graphically the operating characteristics of a typical control mechanism embodying the aforenoted invention.

Line A of the above graph illustrates the pressure setting program of the high blower cam 34,

which in the latter arrangement predominates until the pilot's control lever I is moved to a position corresponding to X. At the latter position, ii. the low blower lies in operation then the cam 33 will control along the line B as the throttle control lever I is adjusted to a further increased position.

However, if the low blower is not in operation then increasing the adjustment of the throttle control lever I will cause the pressure program to follow the line A until the point Y is reached. At the latter point, if the water injection system be in operation, then continued increased adjustment of the lever I will cause the pressure setting program as determined by the cam 35 to follow the line C.

Moreover, the low blower and water injection system, if both be in operation, then upon increased adjustment of the throttle control lever I past the point Z, the cam 35 will control and the pressure setting program will follow the line C.

Moreover the maximum setting of the cams 33 and 34 are limited by the pins I28 and I30 so that low blower and high blower pressure settings will follow the lines D and E respectively at the maximum adjustment of the same. The latter maximum adjustment may be varied by adjustment of the pins I28 and I30.

From the foregoing it will be seen that the cam in operating relation and setting the highest pressure will control. The line A indicates the pressure setting program of the cam 34; the line B indicated the pressure program of the cam 33; while the line C indicated the pressure setting program of the cam 35. Where the pressure setting program of one cam falls below that of the other, such other cam will control.

The relation of the several pressure setting pro- ,grams may be, of course, varied within limits means for automatically adjusting a control device, a first control member for adjusting the datum or said automatic means in accordance with a first predetermined program, a second control member for adjusting the datum of said automatic means in accordance with a diflferent second predetermined program, and another condition responsive means for selectively placing said first and second control members in and out of operative relation with said automatic means.

2. A device of the character described, comprising, in combination, condition responsive means for automatically adjusting a control device, a first control member for adjusting the datum of said automatic means in accordance with a first predetermined program, a second control member for adjusting the datum of said automatic means in accordance with a diflerent second predetermined program, another condition responsive means for selectively placing said first and second control members'in andout of operative relation with said automatic means, and a single manually operable control lever means for simultaneously adjusting said first and second control members and selectively placing said first and second control members in an operative relation with said automatic means.

3. A device of the character described, comprising, in combination, condition responsive means for automatically adjusting a control de vice. a first control member for adjusting the datum of said automatic means in accordance with a first predetermined program, a second control member for adjusting the datum of said automatic means in accordance with a different second predetermined program, and atmospheric pressure responsive means for selectively placing said first and second control members in and out of operative relation with said automatic means.

4. A device of the character described, comprising, in combination, first condition responsive means for automatically adjusting a control device, flrst, second and third control members for adjusting the datum of said automatic means in accordance with predetermined programs, second condition responsive means for placing said second control member in and out of operating relation, third condition responsive means for placing said third control member in and out of operating relation, said second control member so arranged as to control the datum of said automatic means over said first control member, and said third control member so arranged as to control the datum of said automatic means over said first and second control members.

5. A device of the character described, comprising, in combination, first condition responsive means for automatically adjusting a control device, first, second and third control members for adjusting the datum of said automatic means in accordance with predetermined programs, second condition responsive means for placing said second control member in and out of operating relation, third condition responsive means for placing said third control member in and out of operating relation, said second control member so arranged as to control the datum of said automatic means over said first control member, and said third control member so'arranged as to control the datum of said automatic means over said first and second control members, and manually operable means for simultaneously adjusting said first, second and third control members.

6. A device of the character described. comprising, in combination, first condition responsive means for automatically adjusting a control device, first, second and third control members for adjustingthe datum of said automatic means in accordance with predetermined programs, second condition responsive means for placing said second control memlber in and out of operating relation, third condition responsive means for placing said third control member in and out of operating relation, said second control member so arranged as to control the datum of said automatic means over said first control member, and said third control member so arranged as to control the datum of said automatic means over said first and second control members, and manually operable meansfor simultaneously adjusting said first, second and third control members when in said operating relation so as to place the third and then the second of said members out of controlling relation with said automatic means.

7. A device of the character described, comprising, in combination, condition responsive means for automatically adjusting a control device, a control member for adjusting the datum of said automatic means, a plurality of cam members, means for: adjusting said cam mem'bers, followers for said cams, first spring means for biasing said cam followers into contacting relation with said cam members, second spring means for biasing said control member into contacting rel-ation with one of said cam followers, and actuating means for [biasing said one cam follower out of contacting relation with one of said cams so that another of said cam followers may control the position of said control member.

8. A regulator for the induction system of a supercharged aircraft engine, comprising, in combination, a boost control for regulating said induction system so as to maintain the pressure thereof at a predetermined value, first means for changing the datum of said boost control in accordance with a first predetermined program, second means for changing the datum of said boost control in accordance with a different second predetermined program, and condition responsive means for selectively placing said first and second datum changing means in and out of operative relation.

9. The combination comprising a plurality of cams, follower elements for said cams, a pivotally mounted control member, first spring means biasing said cam follower elements into contacting relation with said cams, second spring means biasing said control member in an opposite direction into contacting relation with one of said cam follower elements, and means for actuating said one element out of contacting relation with said control member so as to permit another of said elements to control the position of said control member.

10. The combination comprising three cams rotatably mounted, follower elements for each of said cams, a pivotally mounted control member, first spring means biasing said cam follower elements into contacting relation with said cams, second spring means biasing said control memher in an. opposite direction, one of said cam follower elements limiting the movement of said control member in said opposite direction, motor means for releasably actuating the other of said follower elements out of limiting relation with .said control member so as to permit the one remaining follower element to control the position Y of said control member. 4

11. A throttle control for supercharged aircraft engines, comprising a pilots control lever, an induction throttle valve, means connecting said lever to said throttle valve, a boost control connected to said connecting means and arranged ative relation with said boost control in accordance with altitude.

12. A throttle control for supercharged aircraft engines, comprising a pilots control lever, an induction throttle valve, means connecting said lever to said throttle valve, a boost control connected to said connecting means and arranged to vary the position of said throttle valve relatively to that of said control lever according to the intake manifold pressure of said engine, first means for changingthe datum of said boost control in accordance with a first predetermined program, second means for changing the, datum of said boost control in accordance with a different second predetermined program, means for operating said first and second datum changing means simultaneously by said pilots control lever, and

- means for selectively placing said first and second datum changing means in and out of operative relation with said boost control in accordance with an operating condition of said engine.

13. In an aircraft internal combustion engine a: the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, and means for regulating the pressure in. the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, a pilots control lever operably connectedto said first and second datum changing means, and fluid pressure responsive means for placing the first of said datum changing means in control of said regulating means during the operation of said supplemental fluid injection means, and said fluid pressure responsive means arranged so as to place the second of said datum changing means in control of said regulating means upon cessation of operation. of said supplemental fluid injection means.

14. In an aircraft internal combustion engine of the type including a carburetor for supplying a combustible mixture to said engine, a, supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, third means for changing the daturn of said regulating means. a pilots control lever operably connected to said first, second and third datum changing means, atmospheric pressure responsive means operatively connected to said speed changing means so as to, change the driven speed of said supercharger from a first to a second driven speed at a predetermined atmospheric pressure, and said atmospheric pressure responsive means arranged so as to place the first of said datum changing means in control of said regulating means at the first driven speed and the second of said datum changing means in control of said regulating means at the second driven speed, and supplemental fluid pressure responsive means for placing the third of said datum changing means in control of said regulating means over said first and second datum changing means during operation of said supplemental fluid injection means. t

15. In an aircraft internal combustion engine of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system. of said engine, means for changing the driven speed of said supercharger, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, third means for changing the datum of said regulating means, a pilots control lever operably connected to said first, second and third datum changing means, manually operable means for changing the speed of said supercharger from a first to a second driven speed. and said manually operable means so arranged as to place the first of said datum changing means in. control of said regulating means at the first driven speed and the second of said datum chang-' ing means in control of said regulating means at the second driven sped, and supplemental fluid pressure responsive means for placing the third of said datum changing means in control of said regulating means over said first and second datum changing means during operation of said supplemental fluid injection means.

16. In an aircraft internal combustion. engine of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said su ercharger. operable means for injecting a supplemental fluid for suppressing predetonation of said engine. and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, third means for changing the datum of said regulating means, a pilots control lever operably connected to said first, second and third datum changing means, control means for changing the speed of said supercharger from a first to a second driven speed, and said control means so arranged as to place the first of said datum changing means in control of said regulating means at the first driven speed and the second of said datum changing means in control of said regulating means at the second driven speed, and supplemental fluid pressure responsive means for placing the third of said datum changing means in control of said regulating means over said first and second datum changing means during operation of said supplemental fluid injection means. i

17. In an aircraft internal combustion engine of the type including a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, said second means acting independently of said first means, a pilots control lever operably connected to said first and second datum changing means, operable means connected to said speed changing means and arranged to change the driven speed of said supercharger from a first to a second speed, and said operable means arranged so as to place the first of said datum changing means in control of said regulating means at the first driven speed of said supercharger and the second of said datum changing means in control of said regulating -means at the second driven speed of said super charger.

18. In an aircraft internal combustion engine of the type including a supercharger for supply ing air to the induction system of said engine, means for changing the driven speed of said supercharger, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, said second means acting independently of said first means, a pilots control lever operably connected to said first and second datum changing means, atmospheric pressure responsive means connected to said speed changing means and arranged to change the driven speed of said supercharger from a first to a second speed, and said atmospheric pressure responsive means arranged so as to place the first of said datum changing means in control of said regulating means at the first driven speed of said supercharger and the second of said datum changing means in control of said regulating means at the second driven speed of said supercharger.

19. In an aircraft internal combustion engine of the type including a carburetor for sup-- plying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger, operable means for injecting a supplemental fluid for-suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising a shaft, three cams mounted on said shaft, a pilots control lever operably connected to said shaft, follower elements for each of said cams, a pivotally mounted frame for controlling the datum of said regulator, first spring means for biasing said cam follower elements into contacting relation with said cams, second spring means for biasing said control frame in an opposite direction, one of said cam follower elements limiting the movement of said control frame in said opposite direction, a first motor means for actuating another of the cam follower elements into an inoperative relation during operation of the supercharger at a first driven speed and into a position controlling the position of said control frame at a second driven speed, operable means for controlling the first motor means, a second 

